Question

How many ml of water at 10 degrees c must be added to 75 ml of water at 35 degrees c to obtain a final temperature of 19 c?

Answer 1

[massH2O@10 x specific heatH2O x (Tfinal-Tinitial)]+[massH2O@35 x specific heatH2O x (Tfinal-Tinitial)]=0
Substitute and solve for massH2O@10